package com.atguigu.gulimall.product.service.impl;

import org.springframework.stereotype.Service;

import java.util.Comparator;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> getListTree() {

        // 1.取全分类
        List<CategoryEntity> categoryEntityList = baseMapper.selectList(null);


        // 2.取一级分类
        return categoryEntityList.stream().filter(categoryEntity ->
                        categoryEntity.getParentCid() == 0)
                .map(categoryEntity -> {
                    categoryEntity.setChildren(getChildren(categoryEntity, categoryEntityList));
                    return categoryEntity;
                }).sorted(Comparator.comparingInt(menu ->
                        (menu.getSort() == null ? 0 : menu.getSort()))).collect(Collectors.toList());
    }


    @Override
    public void removeMenuByIds(List<Long> asList) {
        // todo 检查当前删除的菜单是否被别的地方引用

        // 逻辑删除
        baseMapper.deleteBatchIds(asList);

    }

    /**
     * 取当前级别的子级
     *
     * @param categoryEntityCurrent 当前级别
     * @param categoryEntityList    全部数据
     * @return 前级别的子级列表
     */
    private List<CategoryEntity> getChildren(CategoryEntity categoryEntityCurrent,
                                             List<CategoryEntity> categoryEntityList) {

        return categoryEntityList.stream().filter(categoryEntity ->
                categoryEntity.getParentCid().equals(categoryEntityCurrent.getCatId())
        ).map(categoryEntity -> {
            categoryEntity.setChildren(getChildren(categoryEntity, categoryEntityList));
            return categoryEntity;
        }).sorted(Comparator.comparingInt(menu ->
                (menu.getSort() == null ? 0 : menu.getSort()))).collect(Collectors.toList());
    }


}